Seed drills are used to plant seeds. It is desirable to simultaneously fertilize the seed when it is planted and, further, to provide compaction of the soil above the seed and fertilizer since compacted soil will better retain moisture and aid germination. While there exist seed drills which accomplish these objectives, there are inherent disadvantages with these drills.
It is desirable to position the fertilizer below and to the side of the seed in an operation called "side banding". In many drills, the fertilizing and seed planting are accomplished in individual operations which is time consuming or the fertilizer is placed directly with the seed. In other drills, compaction is provided by flat packer wheels. This is disadvantageous since there is no V-shaped furrow to hold moisture in reserve for the germinating seed and there is little protection from the wind and other elements. Some drills provide an unprotected "side banding" seed depositing head that creates its own furrow and runs directly through the soil. Such a head is subject to rapid wear and damage from obstacles in the soil. Other seed drills create an unnecessarily large furrow when it is desirable to disturb as little soil as possible. Some seed drills provide no adjustment to vary the fertilizer deposition depth relative to the seed deposition depth when the seed and fertilizer are being simultaneously and separately planted. Other seed drills provide no opportunity to plant the seed and fertilizer together nor to adjust the proportion of fertilizer with the seed. Other drills provide no adjustment of the hoe points relative to the implement main frame.